Field of the Invention
The present invention relates to technology for imaging a plurality of subjects which are cyclically disposed around a rotary shaft and rotate around the rotary shaft.
Description of the Related Art
In the related art, blades within a jet engine, etc. are observed using an observation scope of an endoscope, etc. Using an image of a subject (an object to be tested) acquired using the observation scope, for example, it is possible to determine the presence/absence of a defect on the subject or measure a size of the defect.